Pump



R. S. NEELY Oct. 24, 1961 PUMP 2 Sheets-Sheet 1 Filed Aug. 10, 1959 INVENTOR.

BY fiwgw Oct. 24, 1961 s, NEELY 3,005,416

PUMP

Filed Aug. 10, 1959 2 Sheets-Sheet 2 3/ If? 30 l I 3J2 )LL txi T #27- FIG. 6

INVENTOR. Midi/1X5 BY PUMP Richard S. Neely, Erie, Pa, assignor to Lord Manufacturing Company, Erie, Pa, a corporation of Pennsylvania Filed Aug. 10, 1959, Ser. No. 832,686 8 Claims. (Cl. 103-117) This invention is a flexible blade rotary pumpdesigned to prevent stress concentration in the blades.

In the drawing, FIG. 1 is a top plan of the pump, FIG. 2 is a section of line 2-2 of FIG. 1, FIG. 3 is a section of line 33 of FIG. 1, FIG. 4 is a top plan of the impeller, FIG. 5 is a section of line 5-5 of FIG. 4, FIG. 6 is a diagram of surfaces for generating the pump housing, FIG. 7 is a section through a modification, and FIG. 8 is a perspective of one of the helical end wall surfaces of the FIG. 7 pump housing.

The pump is shown in a design convenient for outboard motors having a vertical shaft 1 extending through the upper and lower pump housing parts 2 and 3. The pump inlet 4 is in the lower housing part 3 close to the axis of the vertical shaft 1 and the outlet 5 is in the upper pump housing part 2 at the outer part of the housing. By having the inlet at 'a radial distance less than the outlet, the effect of centrifugal force increases the outlet pressure and has a minimtun of interference with the suction. The inlet and outlet each have circumferentially extending sections 6 and 7 substantially diametrically opposite each other and each extending through a substantial are as shown.

Within the pump housing is an impeller having a hub 8 to which is bonded a spider 9 having a pluralityof radial spoke-like projections 10 with oppositely inclined upper and lower conical surfaces 11 and 12 convergingv toward the outer periphery of the impeller. The spokes 10 accordingly have greatest thickness adjacent the hub and least thickness adjacent the periphery of the impeller as indicated in FIG. 3 and at the left hand side of FIG. 5. When viewed from the top there are holes or notches 13 between adjacent spokes 10 which provide free communication between the upper and lower sides of the spider which permits location of the inlet 4 and the outlet 5 on opposite sides of the spider. The spokes 10 are both widest and thickest adjacent the hub 8 where the power is applied to the impeller.

At the center of each of the spokes 10 on both the upper and lower sides are flexible blades 14 having inner and outer axially extending edges 15 and 1 6 converging toward a top 17. In radial cross-section, the blades 14 are of substantially trapezoidal shape as shown at the left in FIG. 5.

The upper and lower pump housing parts have opposite inclined coaxial conical surfaces 18 and 19 engaging the edges 15 of the blades and also have oppositely inclined coaxial conical surfaces 20 and 21 engaging the edges 16 of the blades. The edges 15 and 16 make sealing engagement with the conical surfaces 1821. There may be a slight radial compression of the blades between these' conical surfaces. Between the conical surfaces 18, 20 and 19, 21 are upper and lower helical surfaces 22. 23

which slope radially outward and toward each other in any radial section. The maximum axial separation of the helical surfaces is shown at the left in FIG. 2 and the minimum axial separation of the helical surfaces is shown at the right in FIG. 2. The volume of equiangular segments of the pumping chamber as viewed in FIG. 2. accordingly varies from a maximum at the left to a minimum at the right so that at the inlet 6 the volume is increasing to produce suction while at the outlet 5 the volume is decreasing to produce pressure. In any radial section, the cross section of the cavity of the pump 36 suitably fixed to a shaft 37. The impeller has a housing parts on the upper and lower sides of the spoke is an isosceles trapezoid having as its base dotted lines 24 or 25 respectively coincident with the upper and lower surfaces 11, 12 of the spokes 10 of the pump impeller. The dotted lines 24, 25 as well as the surfaces 11 and 12 on the impeller are perpendicular to obliquely extending lines 26 and 27 through the centers of the blades 14. The lines 26 and 27 are also substantially perpendicular to the helical surfaces 22 and 23 in the pump housing. As the impeller is rotated, the flexible blades 14 are deflected in the manner of a uniformly loaded cantilever beam fixed at one end to the spokes 10 of the impeller. As the impeller rotates, the tips of the blades are main tained in contact with the helical surfaces 22, 23 thereby changing the volume of the chambers between adjacent blades from a maximum whenthe blades occupy the position at the left in FIG. 2 to a minimum when the blades occupy the position at the vright in FIG. 2. With the impeller rotating in the clockwise direction indicated by the arrow in FIG. 1, as the blades pass over the intake 6, the chambers between adjacent blades are expanding, thereby producing a suction drawing liquid into the intake, while as the blades pass over the outlet 7, the chambers between adjacent blades are contracting, thereby expelling liquid through the outlet. The separation between the intake 6 and outlet 7 insures that there is always at least one blade between the intake and outlet preventing leakage from the outlet back to the inlet within the pump housing.

The forces on the blades during rotation of the impeller are such as to maintain contact between the axial edges 15. and 16 of the blades with the associated conical surfaces 18, 19 or 20, 21 as the case may be.- The helical or inclined surfaces 22, 23 on the pump housing pro vide a gradual transition from minimum to maximum deflection of the blades without any abrupt changes which could cause unwanted stresses.

One way of generating the surface of the pump housing is shown in FIG. 6 which illustrates only the upper half of the housing. On centerline 28 are generated conical surfaces 29 and 30 which respectively form the conical surfaces 18 and 20 of the pump housing. On centerline 31 is generated conical surface 32 which forms the inclined or substantially helical surface 22 of the pump housing. The lower half of the pump housing is similarly generated. The conical surfaces 29, 30 and 32 are easily generated on a lathe, resulting in a low mold cost for the pump housing.

In the modification of FIGS. 7 and 8, the end walls of the pump housing are parallel to each other as well as helically disposed about the axis of the pump. This results in uniform stress on the blades and also in slightly greater pumping capacity. The pump housing has upper and lower parts 33, 34 which when secured together form a pump cavity having cylindrical outer surfaces 35.

Within the pump cavity is an impeller made of rubber or other suitable elastomeric material bonded to a hub plurality of angularly spaced rubber blades which in radial cross section in the as molded condition have the generally rectangular cross section indicated at the left in FIG. 7. Adjacent the hub 36 are oppositely projecting integral tubular sleeves 38, 39 which respectively ride against the inner surfaces of tubular projections 40, 41 on the housing parts 33, 34. The tubular sleeves 38, 39 make sealing engagement with the inner surfaces of the projections 40, 41. The tubular projections 40, 41 fit in grooves 42, 43 in the impeller so that the impeller blades are free to flex without stressing the rubber between the impeller and the hub 36. The flexing of the blades is effected by the helical end walls 44, 45 of the FIG. 7 and closest at the right in FIG. 7. The surfaces 44, 45 are true helical surfaces as illustrated in FIG. 8 where there is a uniform axial progression of the surfaces. Accordingly, as the shaft 37 is rotated, the rate of deflection of the impeller blades is uniform. There is no abrupt deflection of any of the blades. As the impeller is rotated, the volume of the cavity between ad jacent blades decreases during the half revolution of the shaft in which the blades move from the position shown at the left to the position shown at the right in FIG. 7 and increases during the succeeding half revolution. The pumping action is accordingly generally the same as in the previously described constructions.

In view of the illustration of the blade carrying spider (FIG. 4), and the liquid inlet and outlet (FIG. 1 and 3), it is not thought necessary to illustrate these features in connection with the FIG. 7 modification.

What is claimed as new is:

1. A rotary pump comprising a pump housing having two pairs of coaxial radially spaced oppositely inclined conical surfaces respectively disposed on opposite sides of the center of the chamber and with the surfaces of each pair extending axially away from the center of the chamber and converging toward each other and the pump housing further having two axially spaced surfaces respectively connecting the conical surfaces of each pair, the axial separation of said connecting surfaces varying from a maximum at one side to a minimum at the diametrically opposite side of the axis of said conical surfaces whereby the volume of equiangular segments of the pumping chamber alternately increases and decreases about the axis of the chamber, an impeller having a plurality of angularly spaced obliquely extending flexible blades bridging the space between the conical and connecting surfaces of the pump housing and deflected obliquely as said impeller is rotated by engagement with said connecting surfaces, and said housing having circumferentially spaced inlet and outlet openings with the outlet opening radially outward of the inlet opening, said inlet being located in a region in which the volume between adjacent blades is increasing as the impeller is rotated and said outlet being located in a region in which the volume between adjacent blades is decreasing as the impeller is rotated.

2. A rotary pump comprising a pump housing having two pairs of coaxial radially spaced oppositely inclined conical surfaces respectively disposed on opposite sides of the center of the chamber and with the surfaces of each pair extending axially away from the center of the chamber and converging toward each other and the pump housing further having two axially spaced surfaces respectively connecting the conical surfaces of each pair, the connecting surfaces being helically disposed so that the axial separation of said connecting surfaces varies from a maximum at one side to a minimum at the diametrically opposite side of the axis of said conical surfaces whereby the volume of equiangular segments of the pumping chamber alternately increases and decreases about the axis of the chamber, an impeller having a plurality of angularly spaced axially extending flexible blades bridging the space between the conical and connecting surfaces of the pump housing and deflected as said impeller is rotated by engagement with said connecting surfaces, and said housing having circumferentially spaced inlet and outlet openings, said inlet being located in a region in which the volume between adjacent blades is increasing as the impeller is rotated and said outlet being located in a region in which the volume between adjacent blades is decreasing as the impeller is rotated.

3. A rotary pump comprising a pump housing having two pairs of coaxial radially spaced oppositely inclined conical surfaces respectively disposed on opposite sides of the center of the chamber and with the surfaces of each pair extending axially away from the center of the chamber and converging toward each other and the pump housing further having two axially spaced surfaces respectively connecting the conical surfaces of each pair, the connecting surfaces being helically disposed so that the axial separation of said connecting surfaces varies from a maximum at one side to a minimum at the diametrically opposite side of the axis of said surfaces whereby the volume of equiangular segments of the pumping chamber alternately increases and decreases about the axis of the chamber, an impeller having a hub with a plurality of angularly spaced radially projecting spokes and flexible blades on the upper and lower sides of each of the spokes bridging the space between the conical and connecting surfaces of the pump housing and deflected axially as said impeller is rotated by engagement with said connecting surfaces, and said housing having circumferentially spaced inlet and outlet openings, said inlet being located in a region in which the volume between adjacent blades is increasing as the impeller is rotated and said outlet being located in a region in which the volume between adjacent blades is decreasing as the impeller is rotated.

4. A rotary pump comprising a pump housing having a pumping chamber in the form of an annular cavity defined by radially spaced circumferential and axially spaced end walls, the axial separation of said end walls varying from a maximum at one side to a minimum at the diametrically opposite side of the cavity whereby the volume of equiangular segments of the pumping chamber alternately increases and decreases about the axis of the chamber, an impeller having a hub with a plurality of angularly spaced radially projecting spokes and flexible blades on the upper and lower sides of each of said spokes engaging the circumferential and end walls of the cavity and being deflected axially as the impeller is rotated by engagement with said end walls, said spokes having inclined upper and lower surfaces converging toward the outer ends of the spokes, said blades being substantially isosceles trapezoids with bases on said converging surfaces of the spokes, said end walls being substantially parallel to the upper and lower surfaces of the spokes, and said housing having circumferentially spaced inlet and outlet openings, said inlet being located in a region in which the volume between adjacent blades is increasing as the impeller is rotated and said outlet being located in a region in which the volume between adjacent blades is decreasing as the impeller is rotated.

5. A rotary pump comprising a pump housing having a pumping chamber in the form of an annular cavity defined by inner and outer cylindrical walls and axially spaced helical end walls, the axial separation of said end walls varying from a maximum at one side to a minimum at the diametrically opposite side of the cavity whereby the volume of equiangular segments of the pumping chamber alternately increases and decreases about the axis of the chamber, an impeller having a hub with a plurality of angularly spaced axially projecting flexible blades engaging the cylindrical and end walls of the cavity and being deflected axially as the impeller is rotated by engagement with said end walls, and said housing having circumferentially spaced inlet and outlet openings, said inlet being located in a region in which the volume between adjacent blades is increasing as the impeller is rotated and said outlet being located in a region in which the volume between adjacent blades is decreasing as the impeller is rotated.

6. A rotary pump comprising a pump housing having a pumping chamber comprising two pairs of coaxial radially spaced oppositely inclined inner and outer conical surfaces respectively converging in one and the opposite axial direction and having two axially spaced conical surfaces on an axis eccentric to the axis of said inner and outer conical surfaces converging radially outward and connecting said inner and outer conical surfaces, the axial separation of said connecting surfaces varying from a maximum at one side to a minimum at the diametrically opposite side of the axis of said inner and outer surfaces whereby the volume of equiangular segments of the pumping chamber alternately increases and decreases about the axis of the chamber, an impeller having a plurality of angularly spaced flexible blades bridging the space between the inner and outer and connecting surfaces of the pump housing and deflected obliquely as said impeller is rotated by engagement with said connecting surfaces, and said housing having circumferentially spaced inlet and outlet openings, said inlet being located in a region in which the volume between adjacent blades is increasing as the impeller is rotated and said outlet being located in a region in which the volume between adjacent blades is decreasing as the impeller is rotated.

7. The pump of claim 6 in which the inlet is radially inward of the outlet so centrifugal force contributes to the outlet pressure without interfering with the suction at the inlet.

8. A rotary pump comprising a pump housing having a pumping chamber in the form of an annular cavity defined by circumferential and end Walls, the end walls being parallel to each other and disposed on helices of opposite pitch whereby the axial separation of said end walls varies from a maximum at one side to a minimum at the diametrically opposite side of the cavity and the volume of equiangular segments of the pumping chamber alternately increases and decreases about the axis of the chamber, an impeller having a plurality of angulariy spaced axially projecting flexible blades engaging the circumferential and end walls of the cavity and being deflected axially as the impeller is rotated by engagement with said end walls, and said housing having circumferentially spaced inlet and outlet openings, said inlet being located in a region in which the volume between afljacent blades is increasing as the impeller is rotated and said outlet being located in a region in which the volume between adjacent blades is decreasing as the impeller is rotated.

References Cited in the file of this patent UNITED STATES PATENTS 2,154,456 Kanpp Apr. 18, 1939 2,517,862 Frederick Aug. 8, 1950 2,542,240 Femstrum Feb. 20, 1951 2,542,268 Weyer Feb. 20, 1951 2,573,819 Weyer Nov. 6, 1951 2,616,374 Carson Nov. 4, 1952 2,649,052 Weyer Aug. 18, 1953 2,734,457 Fernstrum Feb. 14, 1956 2,948,227- Neely Aug. 9, 1960 

